/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.hasor.search.server.servlet;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.common.params.MapSolrParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.ContentStream;
import org.apache.solr.common.util.ContentStreamBase;
import org.apache.solr.core.SolrCore;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.request.SolrRequestHandler;
import org.apache.solr.request.SolrRequestInfo;
import org.apache.solr.response.QueryResponseWriter;
import org.apache.solr.response.SolrQueryResponse;
import org.apache.solr.servlet.SolrRequestParsers;
/**
 * DirectSolrConnection provides an interface to Solr that is similar to
 * the the HTTP interface, but does not require an HTTP connection.
 * 
 * This class is designed to be as simple as possible and allow for more flexibility
 * in how you interface to Solr.
 * 
 *
 * @since solr 1.2
 */
public class DirectSolrConnection {
    protected final SolrCore           core;
    protected final SolrRequestParsers parser;
    /**
     * Initialize using an explicit SolrCore
     */
    public DirectSolrConnection(SolrCore c) {
        core = c;
        parser = new SolrRequestParsers(c.getSolrConfig());
    }
    /**
     * For example:
     * 
     * String json = solr.request( "/select?qt=dismax&wt=json&q=...", null );
     * String xml = solr.request( "/update", "&lt;add&gt;&lt;doc&gt;&lt;field ..." );
     */
    public String request(String pathAndParams, String body) throws Exception {
        String path = null;
        SolrParams params = null;
        int idx = pathAndParams.indexOf('?');
        if (idx > 0) {
            path = pathAndParams.substring(0, idx);
            params = SolrRequestParsers.parseQueryString(pathAndParams.substring(idx + 1));
        } else {
            path = pathAndParams;
            params = new MapSolrParams(new HashMap<String, String>());
        }
        return request(path, params, body);
    }
    public String request(String path, SolrParams params, String body) throws Exception {
        // Extract the handler from the path or params
        SolrRequestHandler handler = core.getRequestHandler(path);
        if (handler == null) {
            if ("/select".equals(path) || "/select/".equalsIgnoreCase(path)) {
                if (params == null)
                    params = new MapSolrParams(new HashMap<String, String>());
                String qt = params.get(CommonParams.QT);
                handler = core.getRequestHandler(qt);
                if (handler == null) {
                    throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "unknown handler: " + qt);
                }
            }
        }
        if (handler == null) {
            throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "unknown handler: " + path);
        }
        return request(handler, params, body);
    }
    public String request(SolrRequestHandler handler, SolrParams params, String body) throws Exception {
        if (params == null)
            params = new MapSolrParams(new HashMap<String, String>());
        // Make a stream for the 'body' content
        List<ContentStream> streams = new ArrayList<ContentStream>(1);
        if (body != null && body.length() > 0) {
            streams.add(new ContentStreamBase.StringStream(body));
        }
        SolrQueryRequest req = null;
        try {
            req = parser.buildRequestFrom(core, params, streams);
            SolrQueryResponse rsp = new SolrQueryResponse();
            SolrRequestInfo.setRequestInfo(new SolrRequestInfo(req, rsp));
            core.execute(handler, req, rsp);
            if (rsp.getException() != null) {
                throw rsp.getException();
            }
            // Now write it out
            QueryResponseWriter responseWriter = core.getQueryResponseWriter(req);
            StringWriter out = new StringWriter();
            responseWriter.write(out, req, rsp);
            return out.toString();
        } finally {
            if (req != null) {
                req.close();
            }
            SolrRequestInfo.clearRequestInfo();
        }
    }
    /**
     * Use this method to close the underlying SolrCore.
     * 
     * @since solr 1.3
     */
    public void close() {
        core.close();
    }
}
